Conventionally, in rotating components such as a blade used in a rotary machine such as a steam turbine or a compressor pump, surface treatment is performed in consideration of heat resistance, corrosion resistance, and so forth. A steam turbine is driven by steam, which serves as a working fluid, being injected into the rotor blades of the turbine. Accordingly, rotary machine components such as rotor blades and rotors of a stream turbine (steam turbine blades) come in direct contact with steam. Moreover, a compressor (compressor pump), which is used at a chemical plant or the like and which compresses various types of fluid, receives power from outside to rotate an impeller, thereby compressing the fluid. Also in this type of compressor pump, rotary machine components such as the impeller and rotor come in direct contact with gas.
Here, in those components such as the blade of the steam turbine and the impeller of the compressor pump, with which water droplets contained in a gas collide at high speed, there is a problem in that the colliding water droplets cause erosion wear to occur on the surface. In those cases where this type of erosion wear occurs, the component vibrates and this vibration may cause damage thereto in some cases.
Furthermore, in the component used in a rotary machine described above, a so-called fouling phenomenon, in which ceramic material such as SiO2 contained in the gas become attached, may occur in some cases. Accordingly, if ceramic material become attached on a component, there is a problem in that the operating efficiency of the component is reduced, and consequently the efficiency of the entire apparatus is reduced.
As a measure for preventing the above erosion wear and fouling, there is generally employed a method in which a film for suppressing the above phenomenon is coated on the substrate surface.
For example, as a measure for suppressing the above erosion wear, there is known a method of using a laminated structure such as illustrated in FIG. 17A and FIG. 17B. This method is a technique in which hard films 103a and 103b composed of TiN, CrN or the like are formed on a base material 101 by means of a physical vapor deposition (PVD) method, and if necessary, an intermediate layer 102 composed of Cr or the like is further formed (for example, refer to Patent Document 1). Moreover, as a measure for suppressing erosion wear, there are known: a method of applying Stellite (registered trademark) cladding by welding; and a method in which a hard film 104 composed of WC—NiCo or the like is formed on a base material 101 by means of thermal spraying as illustrated in FIG. 17C (for example, refer to Patent Documents 2 and 3).
However, this type of erosion resistant hard film described above does not have fouling resistance, and therefore, there is a problem in that the level of the fouling resistance is low despite the improvement having been made in the erosion resistance.
Meanwhile, as the measure for preventing the above fouling, for example, there has been proposed a technique of forming a plated film 111 containing fluorine resin particles on a base material 110 as shown in FIG. 18A. The plated film 111 containing fluorine resin particles is such that fluorine resin particles 111b are dispersed in the plating 111a (for example, refer to Patent Documents 4 and 5). Moreover, there is a method such that a fluorine resin layer 113, in which ceramic particles 113b are dispersed in a fluorine resin 113a, is coated on the base material 110 via a sprayed layer 112 as shown in FIG. 18B. In addition, there is also known a technique of forming a SermaLon coating, which is a fluorine resin based film (for example, refer to Patent Document 6).
Moreover, as the fouling prevention measure, in addition to that described above, there has been proposed a method in which a fluorine resin is coated on a base material in a gas equipment component (for example, refer to Patent Document 7). Furthermore, there has been proposed a method such that a coating containing fluorine, the surface energy of which has been reduced, is formed on a base material (for example, refer to Patent Document 8). Furthermore, there has been proposed a method such that a nitride hard film on a base material is flattened and smoothed to thereby reduce physical adsorption (for example, refer to Patent Document 9).
However, these coatings provided with fouling resistance described above are soft and the level of their erosion resistance is low. Therefore in an environment where a gas comes in direct contact therewith and erosion is likely to occur, there is a problem in that the coating becomes separated.    [Patent Document 1] Japanese Examined Patent Application, Second Publication No. H08-30264    [Patent Document 2] Japanese Unexamined Patent Application, First Publication No. 2004-27289    [Patent Document 3] Japanese Unexamined Patent Application, First Publication No. 2003-27206    [Patent Document 4] Japanese Unexamined Patent Application, First Publication No. 2007-71031    [Patent Document 5] Japanese Unexamined Patent Application, First Publication No. 2007-71032    [Patent Document 6] Japanese Unexamined Patent Application, First Publication No. 2006-291307    [Patent Document 7] Japanese Unexamined Patent Application, First Publication No. 2004-283699    [Patent Document 8] Japanese Unexamined Patent Application, First Publication No. 2007-213715    [Patent Document 9] Japanese Unexamined Patent Application, First Publication No. 2007-162613